[ping] RFR(L): 8221470: Print methods in exception messages in java-like Syntax.

[Lindenmaier, Goetz]

Hi David, 

> Overall this looks good to me - a few minor nits/comments below.
thanks!

> I've applied the patch and am running it through our internal build and
> test system (tiers 1-3 initially).
> 
> I have a suspicion there will be other tests that need to be updated -
> possibly even JCK tests. Discovering those a-priori will be difficult
> (simply running all the tests would take an extremely long time). Will
> have a discussion about how best to handle those internally.

I ran most JCK test without problem. They usually don't check messages.
I ran all hotspot, jdk, langtools, nashorn and jaxp test (except
for headful tests).

> src/hotspot/share/oops/method.cpp
> Please put a blank line after each new method.
Fixed.

> src/hotspot/share/oops/symbol.cpp
> 
> +       os->print(".");
> +     } else {
> +       os->print("%c", start[i]);
> 
> Please use os->put(char c) for individual characters.
Fixed.
 
> The "start" name would seem better as "buf" to me.
Hmm, buf to me is a local chunk of memory used temporarily.
What about array_sig, class_sig?
 
> +     } else if (start[i] == 'L') {
> +       print_class(os, start+i+1, len-i-2);
> Can you insert a comment that help explains the -2:
Done.

> +   for(SignatureStream ss(this); !ss.is_done(); ss.next()) {
> space after for (2 occurrences)
Fixed.

> test/hotspot/jtreg/runtime/exceptionMsgs/methodPrinting/TestPrintingMeth
> ods.java
> 
> Not sure the special characters can be used directly in the sources. Can
> they not be put in as unicode escapes at all places?
I'll try what Ioi proposed.  I'll post a new webrev including that.

Best regards,
  Goetz.


> 
> ---
> 
> Thanks,
> David
> -------
> 
> 
> On 1/04/2019 12:32 pm, David Holmes wrote:
> > Hi Goetz,
> >
> > I'm looking at this ...
> >
> > On 29/03/2019 8:26 pm, Lindenmaier, Goetz wrote:
> >> Hi,
> >>
> >> Any interest in this change?
> >
> > I'm personally of two minds here because these VM generated exceptions
> > are not only delivered to Java source code. I'd like to know how other
> > language developers using the JVM runtime would view this.
> >
> > That aside if you're going to make a change like this then I think the
> > full signature string has to be quoted in some way to delineate it
> > within the larger message.
> >
> >> Should I split it to adapt the exceptions separately one-by-one to
> >> make the change smaller and simplify the review?
> >
> > I don't think that is necessary.
> >
> > Thanks,
> > David
> > -----
> >
> >> I would propose to start out with AbstractMethodError only.
> >>
> >> Best regards,
> >>    Goetz.
> >>
> >>
> >>
> >> From: Lindenmaier, Goetz
> >> Sent: Tuesday, March 26, 2019 1:06 PM
> >> To: hotspot-runtime-dev at openjdk.java.net
> >> Subject: RFR(L): 8221470: Print methods in exception messages in
> >> java-like Syntax.
> >>
> >> Hi,
> >>
> >> A row of exceptions are thrown from the hotspot runtime.
> >> They print methods with their JNI signatures. To increase
> >> readability and resemblance to source code, this change proposes
> >> to print them in a Java-like syntax.
> >>
> >> Some examples:
> >> current method printouts:
> >>
> >> test.TeMe3_B.ma()V
> >> test.TeMe3_B.ma(IZ[[BF)[[D
> >> test.TeMe3_B.ma([[[Ljava/lang/Object;)[[Ltest/TeMe3_B;
> >>
> >> improved format:
> >>
> >> void test.TeMe3_B.ma()
> >> double[][] test.TeMe3_B.ma(int, boolean, byte[][], float)
> >> test.TeMe3_B[][] test.TeMe3_B.ma(java.lang.Object[][][])
> >>
> >> So far, Method::name_and_sig_as_C_string() is used to print
> >> these messages.
> >>
> >> This change implements function Method::external_name() that prints
> >> the better
> >> format.
> >> external_name() is chosen according to Klass::external_name().
> >>
> >> Printing the better format requires parsing the signature
> >> Symbol. This is implemented in
> >> void Symbol::print_as_signature_external_return_type(outputStream *os);
> >> void Symbol::print_as_signature_external_parameters(outputStream *os);
> >> These method names are chosen according to
> >> Symbol::as_class_external_name().
> >>
> >> See this partial webrev for the new functions:
> >> http://cr.openjdk.java.net/~goetz/wr19/8221470-exMsg-signature/01-
> new_methods/
> >>
> >>
> >> Also, I changed a lot of exception messages to use the new format.
> >> This required to adapt a row of tests. I added a test to check
> >> the signature printing does not regress.  For all these changes, see
> >> the full webrev:
> >> http://cr.openjdk.java.net/~goetz/wr19/8221470-exMsg-signature/01/
> >>
> >> I hope I detected all places where method signatures are printed to
> >> exception messages.
> >>
> >> Best regards,
> >>    Goetz.
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>